1. Field of the Invention
The present invention relates generally to an accumulator for an air conditioning system . More particularly, the present invention relates to an accumulator which increases refrigerant flow velocity and improves oil supply to the compressor.
2. Disclosure Information
An air conditioning system conventionally includes a compressor, a condenser, a refrigerant control device, an evaporator and an accumulator arranged as a refrigerant circuit. The compressor compresses the refrigerant for delivery to the condenser, where the state of the refrigerant changes from gaseous to liquid. The liquid refrigerant then passes through the refrigerant control device to the evaporator, where an air blower circulates air over the evaporator to provide cooled air to the vehicle passenger compartment. The resulting heat transfer from passing the ambient air over the evaporator causes the refrigerant to mostly change state from a liquid to a gas, although some liquid does remain.
Liquid and gaseous refrigerant then pass from the evaporator to the accumulator. The accumulator separates the liquid refrigerant from the gaseous refrigerant, allowing only gaseous refrigerant to return to the compressor. The residual liquid refrigerant eventually turns to a gaseous state and is then returned to the compressor. The accumulator also recovers lubricating oil contained in the refrigerant and returns a metered amount of the oil to the inlet side of the compressor.
The accumulator normally comprises an upright cylindrical housing with an inlet opening formed therein and an outlet tube having its mouth in the upper interior region of the accumulator. Refrigerant from the evaporator is introduced into the accumulator through the inlet opening, which may be in the top or in the side of the accumulator housing. The liquid refrigerant settles to the bottom of the accumulator. Gaseous refrigerant rises to the top of the accumulator, where suction by the compressor draws the gaseous refrigerant through the outlet tube. Typically, the outlet tube is a J-shaped tube having an oil inlet at the bottom or curved part of the J-shaped tube. The gaseous refrigerant enters the top opening of the tube and travels along its complete length before exiting the accumulator. Manufacturing a J-shaped tube is labor intensive and complex.
During a low charge/low oil system condition in the refrigerant circuit, the compressor can be damaged if the volume of oil returned to the compressor is too low. Oil is used to lubricate the moving members within the compressor. Typically, the outlet tube of the accumulator includes the metering or oil return orifice located at the bottom of the outlet tube adjacent the bottom of the accumulator housing for drawing oil pooled along the bottom of the accumulator into the tube which passes the oil to the compressor. Flow of the refrigerant through the outlet tube draws the oil from the oil return orifice and carries it to the compressor. Higher flow velocities increase the drawing of the oil into the outlet tube.
Therefore it would be advantageous to provide an accumulator which provides increased flow velocity of refrigerant through the outlet tube to increase the amount of oil returned to the compressor.
It is an object of the present invention to provide an accumulator which is cheaper and easier to manufacture and which increases the flow velocity of the refrigerant leaving the accumulator.